I have an award ticket booked for 150K Skymiles on all VA metal with the current flights. The long haul is in J, while the shorter legs are in Y.

VA: LAX-SYD(J)-ZQN(Y)
VA: DUD-BNE(Y)-SYD-LAX(J)

I'm wanting to change my outbound to DL metal in J, which only has 'standard' award level. I was expecting 45K more miles (90/2) for the change. However, I've called twice and each time they price it at 105K more. Their explanation is that I can't mix DL 'standard' and VA 'saver', so the VA 'saver' legs take more miles in addition to the miles needed for the DL standard ticket.

Is that really true? Seems to me that using a DL 'standard' J award would allow through ticketing on VA 'saver' without more miles. Both agents said with the VA partner that the segments must be priced separately.